This invention relates generally to a method and apparatus for tracing cables and, more particularly, to a system which utilizes a pulsing electrical load in combination with a standard clamp-on type ammeter for quickly, conveniently and reliably tracing electrical cables within a building.
Over the years the electrical power wiring diagrams and drawings for building can become either lost or obsolete. After a period of time, when it becomes necessary to perform electrical work within the building or to rearrange the rooms therein, it becomes difficult to determine which circuit breaker controls a specific outlet within the building.
Heretofore, there have been basically two procedures by which to trace the electrical cables within a building and reestablish an electrical wiring diagram:
(1) THE MOST OBVIOUS WAY IN WHICH TO TRACE THESE CIRCUITS WOULD BE TO PLUG A LAMP INTO THE OUTLET IN QUESTION AND SWITCH THE CIRCUIT BREAKERS OFF MOMENTARILY, IN TURN, UNTIL THE LAMP WITHIN THE OUTLET GOES OFF. Unfortunately, this method is annoying for workers if used during normal office hours. For example, such a method could conceivably pose an extreme safety hazard when, for instance, an improper outlet has been momentarily shut off and a heavy object is being lifted by workers in a suddently darkened area. Furthermore, the interruption of power may be extremely harmful to office equipment, such as copying machines. Finally, the above method may not even work in an efficient manner, since, if the controlled outlet is very far, or around corners, from the circuit breaker the operation of the outlet in question would be hard to monitor; and
(2) METAL DETECTORS OR THE LIKE CAN BE USED TO TRACE CABLES WITHIN THE WALLS OF BUILDING UNDER CERTAIN CIRCUMSTANCES. Unfortunately, this apparatus yields an uncertain approach when the cables in question are crowded together.
What is needed is an electrical cable tracing system which is extremely reliable in the tracing of electrical circuits and in addition provides a minimum of inconvenience to those who are involved in utilizing outlets which are not a problem.